Background: The aim of this study was to evaluate the association between the noggin rs227731 polymorphism on chromosome 17q22 and risk of nonsyndromic cleft lip with or without palate (NSCL/P).
Methods: Three online databases were searched, including Embase, PubMed, and Chinese National Knowledge Infrastructure. The strength of the associations was evaluated by odds ratios (ORs) and 95% confidence intervals (CIs). We also made a subgroup analysis to explore sources of heterogeneity.
Results: Nine comparisons from seven studies were included in this meta-analysis. We used five genetic models and found that the noggin rs227731 polymorphism may increase NSCL/P risk in Caucasians: C versus A: OR = 1.43, 95% CI, 1.30-1.58; CC versus AA: OR = 2.00, 95% CI, 1.59-2.52; CA versus AA: OR = 1.50, 95% CI, 1.27-1.77; CC+CA versus AA: OR = 1.64, 95% CI, 1.40-1.92; CC versus CA+AA: OR = 1.56, 95% CI, 1.30-1.87. However, for the Chinese population, no significant association between the rs227731 polymorphism and NSCL/P risk was found: C vs. A: OR = 1.04, 95% CI, 0.81-1.33; CC vs. AA: OR = 1.01, 95% CI, 0.52-1.95; CA vs. AA: OR = 1.03, 95% CI, 0.75-1.40; CC+CA vs. AA: OR = 1.04, 95% CI, 0.76-1.43; CC vs. CA+AA: OR = 1.01, 95% CI, 0.56-1.81.
Conclusion: Our meta-analysis suggested that the rs227731 polymorphism may increase NSCL/P risk in Caucasians and may have no significant association in the Chinese population. Effects of individual and environmental risk factors and of gene-environment interactions may play a different role in Caucasians than in the Chinese population. More relevant case-control studies are required to obtain more precise results. Birth Defects Research 109:445-451, 2017. © 2017 Wiley Periodicals, Inc.
Keywords: cleft palate polymorphism; genetic meta-analysis.
© 2017 Wiley Periodicals, Inc.